Question: what are the mathematical notation which start with the letter s
Paraphrase: what are the numerical documentation which begin with the letter s
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q1140046 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 's')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: Schläfli symbol, Schläfli symbol, Sweedler notation, Sweedler notation